Research Group MOVANT, Department of Rehabilitation Sciences and Physiotherapy (REVAKI), University of Antwerp, Wilrijk, Belgium.
Pain in Motion research group, http://www.paininmotion.be/, Belgium.
Eur J Pain. 2021 Jan;25(1):243-256. doi: 10.1002/ejp.1665. Epub 2020 Oct 14.
Conditioned pain modulation (CPM) methods are experimental procedures to assess presumed descending nociceptive modulatory pathways. Various CPM-methods are currently used, making the comparison of results difficult. The aim of this study was to compare five conditioning stimuli and to evaluate the influencing effects of personal factors on CPM-efficacy.
101 healthy pain-free adults (50 males, 51 females) participated in this cross-sectional study with repeated measures design. The CPM-method consisted of hot water immersion (46°C, HWI), cold pressor test (12°C, CPT), cold pack application, and single and double ischemic occlusion as conditioning stimuli in randomized order. Pressure pain threshold was used as test stimulus at the mm. trapezius and quadriceps for all CPM-protocols.
All CPM-protocols resulted in effective CPM, although cold pack application revealed smaller CPM-magnitudes compared to all other methods at both muscles, except single ischemic occlusion at the m. quadriceps. A smaller CPM-effect at the m. trapezius was shown when CPM was provoked by single ischemic occlusion compared to the CPT. Chronic stress, gender, attentional focus, age, physical activity and perceived pain are all influencing factors, in various conditioning stimuli at the mm. trapezius and quadriceps.
CPT and HWI seem to be the most appropriate conditioned pain modulation paradigms for research settings, while single and double ischemic occlusion seem to be more useful for clinical settings. Influencing factors to be considered are gender, age, stress, physical activity, perceived pain and attentional focus to the conditioning stimulus, but depend on the test site and exerted method.
Hot water immersion, cold pressor test, and single and double ischemic occlusion result in comparable CPM-effects at the mm. trapezius and quadriceps. Anti-nociceptive effects of the cold pack are mainly a result of attention towards the cold pack. Chronic stress, attentional focus towards the conditioning stimulus and perceived pain of the conditioning stimulus influenced the anti-nociceptive effects at the m. trapezius. Gender and level of physical activity influenced the anti-nociceptive effects with the other methods at the m. quadriceps.
条件性疼痛调制（CPM）方法是评估假定的下行疼痛调制途径的实验程序。目前使用各种 CPM 方法，使得结果比较困难。本研究的目的是比较五种调节刺激，并评估个人因素对 CPM 效果的影响。
101 名健康无痛的成年人（50 名男性，51 名女性）参加了这项横断面研究，采用重复测量设计。CPM 方法包括热水浸泡（46°C，HWI）、冷压测试（12°C，CPT）、冷包应用以及单双缺血闭塞作为随机顺序的调节刺激。在所有 CPM 方案中，使用压力疼痛阈值作为测试刺激在斜方肌和股四头肌。
所有 CPM 方案均产生有效的 CPM，尽管冷包应用在斜方肌和股四头肌的所有其他方法中除单缺血闭塞外，其 CPM 幅度较小。与 CPT 相比，斜方肌单缺血闭塞引起的 CPM 效应较小。慢性应激、性别、注意力焦点、年龄、身体活动和感知疼痛是斜方肌和股四头肌各种调节刺激的影响因素。
CPT 和 HWI 似乎是研究环境中最适合的条件性疼痛调制范式，而单双缺血闭塞似乎更适合临床环境。要考虑的影响因素是性别、年龄、压力、身体活动、对调节刺激的感知疼痛和注意力焦点，但取决于测试部位和施加的方法。
热水浸泡、冷压测试和单双缺血闭塞在斜方肌和股四头肌均产生可比的 CPM 效应。冷包的抗伤害作用主要是由于对冷包的注意力。慢性应激、对调节刺激的注意力焦点和调节刺激的感知疼痛影响斜方肌的抗伤害作用。性别和身体活动水平影响其他方法在股四头肌的抗伤害作用。
